(pseudo) incremental backup with different exclude lists using hardlinks and rsync
ccollect is a backup utitily written in the sh-scripting language. It does not depend on a specific shell, only /bin/sh needs to be bourne shell compatibel (like dash, ksh, zsh, bash, …).
While thinking about the design of ccollect, I thought about enabling backup to remote hosts. Though this sounds like a nice feature (Backup my notebook to the server now.), it is in my opinion a bad idea to backup to a remote host, because you have to open security at your backup host. Think of the following situation: You backup your farm of webservers to a backup host somewhere else. One of your webservers gets compromised, then your backup server will be compromised, too. Think of it the other way round: The backup server (now behind a firewall using NAT and strong firewall rules) connects to the webservers and pulls the data from them. If someone gets access to one of the webservers, the person will perhaps not even see your machine. If he/she sees that there are connections from a host to the compromised machine, he/she will not be able to login to the backup machine. All other backups are still secure.
For the installation, you need at least
either cp and chmod or install
for more comfort: make
for rebuilding the generated documentation: additionally asciidoc
bc
cp with support for hard links (cp -al)
date
rsync
ssh (if you want to use rsync over ssh, which is recommened for security)
Either type make install or simply copy it to a directory in your $PATH and execute chmod 0755 /path/to/ccollect.sh.
ccollect looks for its configuration in /etc/ccollect or, if set, in the directory specified by the variable $CCOLLECT_CONF (use CCOLLECT_CONF=/your/config/dir ccollect.sh on the shell).
When you start ccollect, you have either to specify which intervall to backup (daily, weekly, yearly; you can specify the names yourself, see below).
The intervall is used to specify how many backups to keep.
There are also some self explaining parameters you can pass to ccollect, simply use "ccollect.sh —help" for info.
The general configuration can be found below $CCOLLECT_CONF/defaults or /etc/ccollect/defaults. All options specified here are generally valid for all source definitions. Though the values can be overwritten in the source configuration.
All configuration entries are plain-text (use UTF-8 if you use non ASCII characters) files.
The intervall definition can be found below $CCOLLECT_CONF/defaults/intervalls/ or /etc/ccollect/defaults/intervalls. Every file below this directory specifies an intervall. The name of the file is the name of the intervall: intervalls/<intervall name>.
The content of this file should be a single line containing a number. This number defines how many versions of this intervall to keep.
Example:
[10:23] zaphodbeeblebrox:ccollect-0.2% ls -l conf/defaults/intervalls/ insgesamt 12 -rw-r--r-- 1 nico users 3 2005-12-08 10:24 daily -rw-r--r-- 1 nico users 3 2005-12-08 11:36 monthly -rw-r--r-- 1 nico users 2 2005-12-08 11:36 weekly [10:23] zaphodbeeblebrox:ccollect-0.2% cat conf/defaults/intervalls/* 28 12 4
This means to keep 28 daily backups, 12 monthly backups and 4 weekly.
If you add $CCOLLECT_CONF/defaults/pre_exec or /etc/ccollect/defaults/pre_exec (same with post_exec), ccollect will start pre_exec before the whole backup process and post_exec after backup of all sources is done.
The following example describes how to report free disk space in human readable format before and after the whole backup process:
[13:00] hydrogenium:~# mkdir -p /etc/ccollect/defaults/ [13:00] hydrogenium:~# echo '!/bin/sh' > /etc/ccollect/defaults/pre_exec [13:01] hydrogenium:~# echo '' >> /etc/ccollect/defaults/pre_exec [13:01] hydrogenium:~# echo 'df -h' >> /etc/ccollect/defaults/pre_exec [13:01] hydrogenium:~# chmod 0755 /etc/ccollect/defaults/pre_exec [13:01] hydrogenium:~# ln -s /etc/ccollect/defaults/pre_exec /etc/ccollect/defaults/post_exec
Each source configuration exists below $CCOLLECT_CONF/sources/$name or /etc/ccollect/sources/$name.
The name you choose for the subdirectory describes the source.
Each source has at least the following files:
source (a text file containing the rsync compatible path to backup)
destination (a link to the directory we should backup to)
Additionally a source may have the following files:
verbose whether to be verbose (passes -v to rsync)
very_verbose be very verbose (-v also for mkdir, cp, rm)
summary create a transfer summary when rsync finished
exclude exclude list for rsync. newline (\n) seperated list.
rsync_options' extra options to pass to `rsync
pre_exec program to execute before backuping this source
post_exec program to execute after backuping this source
Example:
[10:47] zaphodbeeblebrox:ccollect-0.2% ls -l conf/sources/testsource2 insgesamt 12 lrwxrwxrwx 1 nico users 20 2005-11-17 16:44 destination -> /home/nico/backupdir -rw-r--r-- 1 nico users 62 2005-12-07 17:43 exclude drwxr-xr-x 2 nico users 4096 2005-12-07 17:38 intervalls -rw-r--r-- 1 nico users 15 2005-11-17 16:44 source [10:47] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/exclude openvpn-2.0.1.tar.gz nicht_reinnehmen etwas mit leerzeichenli [10:47] zaphodbeeblebrox:ccollect-0.2% ls -l conf/sources/testsource2/intervalls insgesamt 4 -rw-r--r-- 1 nico users 2 2005-12-07 17:38 daily [10:48] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/intervalls/daily 5 [10:48] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/source /home/nico/vpn
source describes a rsync compatible source (one line only).
For instance backup_user@foreign_host:/home/server/video. To use the rsync protocol without the ssh-tunnel, use rsync::USER@HOST/SRC. For more information have a look at rsync(1).
verbose tells ccollect that the log should contain verbose messages.
If this file exists in the source specification -v will be passed to rsync.
Example:
[11:35] zaphodbeeblebrox:ccollect-0.2% touch conf/sources/testsource1/verbose
very_verbose tells ccollect that it should log very verbose.
If this file exists in the source specification -v will be passed to rsync, cp, rm and mkdir.
Example:
[23:67] nohost:~% touch conf/sources/testsource1/very_verbose
If you create the file summary below the source definition, ccollect will present you with a nice summary at the end.
backup:~# touch /etc/ccollect/sources/root/summary backup:~# ccollect.sh werktags root ==> ccollect.sh: Beginning backup using intervall werktags <== [root] Beginning to backup this source ... [root] Currently 3 backup(s) exist, total keeping 50 backup(s). [root] Beginning to backup, this may take some time... [root] Hard linking... [root] Transferring files... [root] [root] Number of files: 84183 [root] Number of files transferred: 32 [root] Total file size: 26234080536 bytes [root] Total transferred file size: 9988252 bytes [root] Literal data: 9988252 bytes [root] Matched data: 0 bytes [root] File list size: 3016771 [root] File list generation time: 1.786 seconds [root] File list transfer time: 0.000 seconds [root] Total bytes sent: 13009119 [root] Total bytes received: 2152 [root] [root] sent 13009119 bytes received 2152 bytes 2891393.56 bytes/sec [root] total size is 26234080536 speedup is 2016.26 [root] Successfully finished backup. ==> Finished ccollect.sh <==
You could also combine it with verbose or very_verbose, but they already print some statistics (but not all / the same as presented by summary).
exclude specifies a list of paths to exclude. The entries are new line (\n) seperated.
Example:
[11:35] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/exclude openvpn-2.0.1.tar.gz nicht_reinnehmen etwas mit leerzeichenli something with spaces is not a problem
destination must be a link to the destination directory.
Example:
[11:36] zaphodbeeblebrox:ccollect-0.2% ls -l conf/sources/testsource2/destination lrwxrwxrwx 1 nico users 20 2005-11-17 16:44 conf/sources/testsource2/destination -> /home/nico/backupdir
To speak truth, this is not fully correct. ccollect will also backup your data, if destination is a directory. But do you really want to have a backup below /etc?
When you create a subdirectory intervalls/ within your source configuration directory, you can specify individiual intervalls for this specific source. Each file below this directory describes an intervall.
Example:
[11:37] zaphodbeeblebrox:ccollect-0.2% ls -l conf/sources/testsource2/intervalls/ insgesamt 8 -rw-r--r-- 1 nico users 2 2005-12-07 17:38 daily -rw-r--r-- 1 nico users 3 2005-12-14 11:33 yearly [11:37] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/intervalls/* 5 20
When you create the file rsync_options below your source configuration, all the parameters found in this file will be passed to rsync. This way you can pass additional options to rsync. For instance you can tell rsync to show progress ("—progress") or which -password-file ("—password-file") to use for automatic backup over the rsync-protocol.
Example:
[23:42] hydrogenium:ccollect-0.2% cat conf/sources/test_rsync/rsync_options --password-file=/home/user/backup/protected_password_file
When you create pre_exec and / or post_exec below your source configuration, ccollect will execute this command before, respective after doing the backup for this specific source. If you want to have pre-/post-exec before and after all backups, see above for general configuration.
Example:
[13:09] hydrogenium:ccollect-0.3% cat conf/sources/with_exec/pre_exec #!/bin/sh # Show whats free before df -h [13:09] hydrogenium:ccollect-0.3% cat conf/sources/with_exec/post_exec #!/bin/sh # Show whats free after df -h
When you have a computer with little computing power, it may be useful to use rsync without ssh, directly using the rsync protocol (specify user@host::share in source). You may wish to use rsync_options to specify a password file to use for automatic backup.
Example:
backup:~# cat /etc/ccollect/sources/sample.backup.host.org/source backup@webserver::backup-share backup:~# cat /etc/ccollect/sources/sample.backup.host.org/rsync_options --password-file=/etc/ccollect/sources/sample.backup.host.org/rsync_password backup:~# cat /etc/ccollect/sources/sample.backup.host.org/rsync_password this_is_the_rsync_password
This hint was reported by Daniel Aubry.
When you exclude "/proc" or "/mnt" from your backup, you may run into trouble when you restore your backup. When you use "/proc/*" or "/mnt/*" instead ccollect will backup empty directories.
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Note
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When those directories contain hidden files (those beginning with a dot (.)), they will still be transferred! |
This hint was reported by Marcus Wagner.
If you used rsync directly before you use ccollect, you can use this old backup as initial backup for ccollect: You simply move it into a subdirectory named "intervall.0".
Example:
backup:/home/backup/web1# ls bin dev etc initrd lost+found mnt root srv usr vmlinuz boot doc home lib media opt sbin tmp var vmlinuz.old backup:/home/backup/web1# mkdir daily.0 # ignore error about copying to itself backup:/home/backup/web1# mv * daily.0 2>/dev/null backup:/home/backup/web1# ls daily.0
Now you could use /home/backup/web1 as the destination for the backup.
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Note
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Do not name the first backup something like "daily.initial", but use the "0" (or some very low number, at least lower than the current year) as extension. ccollect uses sort to find the latest backup. ccollect itself uses intervall.YEAR-MONTH-DAY-HOUR:MINUTE.PID. This notation will always be before "daily.initial", as numbers are earlier in the list which is produced by sort. So, if you have a directory named "daily.initial", ccollect will always diff against this backup and transfer and delete files which where deleted in previous backups. This means you simply waste resources, but your backup will be complete. |
Your pre_/post_exec script does not need to be a script, you can also use a link to
an existing program
an already written script
The only requirement is that it is executable.
Let us assume, that one backup failed (connection broke or hard disk had some failures). So we've one backup in our history, which is incomplete.
The next time you use ccollect, it will transfer the missing files
No. ccollect passes your source definition directly to rsync. It does not try to analyze it. So it actually does not know if a source comes from local harddisk or from a remote server. And it does not want to. When you backup from the local harddisk (which is perhaps not even a good idea when thinking of security) add the destination to source/exclude. (Daniel Aubry reported this problem)
The most common error is to not give your script the correct permissions. Try chmod 0755 /etc/ccollect/sources/yoursource/*_exec`.
srwali01:~# mkdir /etc/ccollect srwali01:~# mkdir -p /etc/ccollect/defaults/intervalls/ srwali01:~# echo 28 > /etc/ccollect/defaults/intervalls/taeglich srwali01:~# echo 52 > /etc/ccollect/defaults/intervalls/woechentlich srwali01:~# cd /etc/ccollect/ srwali01:/etc/ccollect# mkdir sources srwali01:/etc/ccollect# cd sources/ srwali01:/etc/ccollect/sources# ls srwali01:/etc/ccollect/sources# mkdir local-root srwali01:/etc/ccollect/sources# cd local-root/ srwali01:/etc/ccollect/sources/local-root# echo / > source srwali01:/etc/ccollect/sources/local-root# cat > exclude << EOF > /proc > /sys > /mnt > EOF srwali01:/etc/ccollect/sources/local-root# ln -s /mnt/hdbackup/local-root destination srwali01:/etc/ccollect/sources/local-root# mkdir /mnt/hdbackup/local-root srwali01:/etc/ccollect/sources/local-root# ccollect.sh taeglich local-root /o> ccollect.sh: Beginning backup using intervall taeglich /=> Beginning to backup "local-root" ... |-> 0 backup(s) already exist, keeping 28 backup(s).
After that, I added some more sources:
srwali01:~# cd /etc/ccollect/sources srwali01:/etc/ccollect/sources# mkdir windos-wl6 srwali01:/etc/ccollect/sources# cd windos-wl6/ srwali01:/etc/ccollect/sources/windos-wl6# echo /mnt/win/SYS/WL6 > source srwali01:/etc/ccollect/sources/windos-wl6# ln -s /mnt/hdbackup/wl6 destination srwali01:/etc/ccollect/sources/windos-wl6# mkdir /mnt/hdbackup/wl6 srwali01:/etc/ccollect/sources/windos-wl6# cd .. srwali01:/etc/ccollect/sources# mkdir windos-daten srwali01:/etc/ccollect/sources/windos-daten# echo /mnt/win/Daten > source srwali01:/etc/ccollect/sources/windos-daten# ln -s /mnt/hdbackup/windos-daten destination srwali01:/etc/ccollect/sources/windos-daten# mkdir /mnt/hdbackup/windos-daten # Now add some remote source srwali01:/etc/ccollect/sources/windos-daten# cd .. srwali01:/etc/ccollect/sources# mkdir srwali03 srwali01:/etc/ccollect/sources# cd srwali03/ srwali01:/etc/ccollect/sources/srwali03# cat > exclude << EOF > /proc > /sys > /mnt > /home > EOF srwali01:/etc/ccollect/sources/srwali03# echo 'root@10.103.2.3:/' > source srwali01:/etc/ccollect/sources/srwali03# ln -s /mnt/hdbackup/srwali03 destination srwali01:/etc/ccollect/sources/srwali03# mkdir /mnt/hdbackup/srwali03
# du (coreutils) 5.2.1 [10:53] srsyg01:sources% du -sh ~/backupdir 4.6M /home/nico/backupdir [10:53] srsyg01:sources% du -sh ~/backupdir/* 4.1M /home/nico/backupdir/daily.2005-12-08-10:52.28456 4.1M /home/nico/backupdir/daily.2005-12-08-10:53.28484 4.1M /home/nico/backupdir/daily.2005-12-08-10:53.28507 4.1M /home/nico/backupdir/daily.2005-12-08-10:53.28531 4.1M /home/nico/backupdir/daily.2005-12-08-10:53.28554 4.1M /home/nico/backupdir/daily.2005-12-08-10:53.28577 srwali01:/etc/ccollect/sources# du -sh /mnt/hdbackup/wl6/ 186M /mnt/hdbackup/wl6/ srwali01:/etc/ccollect/sources# du -sh /mnt/hdbackup/wl6/* 147M /mnt/hdbackup/wl6/taeglich.2005-12-08-14:42.312 147M /mnt/hdbackup/wl6/taeglich.2005-12-08-14:45.588
The backup of our main fileserver:
backup:~# df -h /home/backup/srsyg01/
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/backup--01-srsyg01
591G 451G 111G 81% /home/backup/srsyg01
backup:~# du -sh /home/backup/srsyg01/*
432G /home/backup/srsyg01/daily.2006-01-24-01:00.15990
432G /home/backup/srsyg01/daily.2006-01-26-01:00.30152
434G /home/backup/srsyg01/daily.2006-01-27-01:00.4596
435G /home/backup/srsyg01/daily.2006-01-28-01:00.11998
437G /home/backup/srsyg01/daily.2006-01-29-01:00.19115
437G /home/backup/srsyg01/daily.2006-01-30-01:00.26405
438G /home/backup/srsyg01/daily.2006-01-31-01:00.1148
439G /home/backup/srsyg01/daily.2006-02-01-01:00.8321
439G /home/backup/srsyg01/daily.2006-02-02-01:00.15383
439G /home/backup/srsyg01/daily.2006-02-03-01:00.22567
16K /home/backup/srsyg01/lost+found
backup:~# du --version | head -n1
du (coreutils) 5.2.1
Newer versions of du also detect the hardlinks, so we can even compare the sizes directly with du:
[8:16] eiche:~# du --version | head -n 1 du (GNU coreutils) 5.93 [8:17] eiche:schwarzesloch# du -slh hydrogenium/* 19G hydrogenium/durcheinander.0 18G hydrogenium/durcheinander.2006-01-17-00:27.13820 19G hydrogenium/durcheinander.2006-01-25-23:18.31328 19G hydrogenium/durcheinander.2006-01-26-00:11.3332 [8:22] eiche:schwarzesloch# du -sh hydrogenium/* 19G hydrogenium/durcheinander.0 12G hydrogenium/durcheinander.2006-01-17-00:27.13820 1.5G hydrogenium/durcheinander.2006-01-25-23:18.31328 200M hydrogenium/durcheinander.2006-01-26-00:11.3332
In the second report (without -l) the sizes include the space the inodes of the hardlinks allocate.